Abstract: Objective  To observe the expression and distribution of polycystin-1(PC-1)and polycystin-2(PC-2) in ameloblastom, and compared with the odontogenic keratocysts, so as to provide clues for the study of the pathogenesis and development of ameloblastoma and the search for new treatment methods.
  Methods  The expression and distribution of PC-1 and PC-2 in 30 ameloblastomas and 15 odontogenic keratocysts were detected by immunohistochemistry.
  Results  Compared with odontogenic keratocyst group, the positive expression rate of PC-1 and PC-2 in ameloblastoma group was significantly higher (P＜0.05). The two proteins were distributed in the cytoplasm and membrane of ameloblast like cells, some stellate reticular like cells, squamous metaplasia and cystic tumor cells in ameloblastoma, as well as in the echinoderm, granular layer and some basal cells lined with odontogenic keratocyst epithelium.There was no difference in the distribution and expression of PC-1 and PC-2 between solid or multicystic and monocystic ameloblastoma and multicystic ameloblastoma(P＜0.05).
  Conclusion  Polycystin may be involved in the epithelial stromal transformation of ameloblastoma, and its high expression may be related to the occurrence and development of ameloblastoma, the cystic transformation and biological behavior of the tumor, but not to the formation of cyst.

Key words: ameloblastoma, odontogenic cysts, polycystin